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22 Class Presentation for VLSI Course Major Reference is: Circuit Design Issues in Multi-Gate FET CMOS Technologies Christian Pacha, Klaus VonArnim, Thomas Schulz, Wade Xiong, Michael Gostkowski, Gerhard Knoblinger, Andrew Marshal, Thomas Nirschl, Joerg Berthold, Christian Russ, Harald Gossner, Charvaka Duvvury, Paul Patruno, C. Rinn Cleavelin, Klaus Schruefer Instructor: S. M. Fakhraee Presented by: Behzad Ebrahimi December 2006 In ISSCC2006/ SESSION 23/ TECHNOLOGY AND ARCHITECTURE DIRECTIONS/ 23.2

33 Outline Introduction Comparison speed in different structures Low power design Opamp with FinFET I/O and ESD protection

4 Introduction 4 Multiple-Gate FET Transistors are promising device structures for sub-45nm technology. Superior Control of the Channel Reduced Short Channel Effect Lower Leakage Current Better Cicuit Performance Novel Gate-Stack materials Reduced parasitic capacitances Hole mobility improvement

5 Multi-Gate FET TriGate Double Gate/ FinFET W FIN L H FIN

66 Multi-Gate FET Fabrication of tall Triple-Gate FETs with 10nm fin with demonstrates the long-term scalability. Relaxed FinFET and Triple- Gate device dimensions were chosen to increase yield and homogeneity. Triple-Gate Control allows for higher device currents and relaxed process requirements. From [1]

77 Multi-Fin MuGFET FinFET: Triple-Gate FET: Footprint: Area gain over bulk CMOS: Three-dimensional device topology in combination with a small fin pitch improves the circuit density. From [1]

8 Multi-Fin MuGFET The discrete transistor widths of multi-fin MUGFETs are a circuit design limitation compared to bulk CMOS. This design limitation is not critical for nFET/pFET sizing in CMOS logic circuits, especially for a channel surface orientation [1] Discrete transistor widths are a concern for SRAM cells which are composed of single-fin devices. In SRAM the drive currents of single-fin MUGFETs can be modified only by different gate lengths.

99 Speed in Different Structure Performance, active and leakage current of these structures are measured using 24 ring oscillator (RO) modules. The ROs are composed of various gates up to NAND3/NOR3 complexity with a fan out two (FO2). Triple-Gate circuits using TiN metal gate electrodes are 65% faster than FinFET circuits with poly-Si gate electrodes at VDD=1.2V. From [1]

10 Low Power Design 10 Low power circuits require additional high-V T devices to implement non- critical paths to switch-off non-active circuit blocks. Fast circuit are based on devices with minimum gate length while leakage sensetive circuits are made of devices with longer gate lengths but smaller off-currents. From [1]

11 Operational Amplifier Due to the large multi-fin transistors with non-minimum gate lengths, the effect of discrete device widths on circuit design is negligible. Bode plot ( gain vs. frequency) configured as a 20dB inverting amplifier. The low-frequency open loop gain is A 0 =45dB. This is comparable with typical open loop gains achievable in deep sub-micron planar CMOS technologies. From [3]

12 I/O & ESD  MuGFETs show a low ESD current capability and high ESD sensitivity.  This motivates the co-integration of more robust PD-SOI devices for ESD clamps and multi-fin MuGFETs to provide large currents for fast I/O drivers. From [1]

13 Conclusion Three-dimensional device topology in combination with a small fin pitch in multifin MuGFET improves the circuit density Novel Gate-Stack materials can improve performance. The use of FinFET in low power applications is considered. The successful design and realization of the most important analog circuits (Miler op-amp) in a MuGFET technology is presented for the first time. We see a solution to the electrostatic discharge (ESD) sensitivity of MuGFETs.

14 THANKS FOR YOUR ATTENTION ANY QUESTION?

15 References: 1. C. Pacha et al., “Circuit Design Issues in Multi-Gate FET CMOS Technologies,” ISSCC Dig. Tech Papers, pp , February., N. Collaert et-al, “A Functional 41-Stage Ring Oscillator Using Scaled FinFET Devuces WIth 25-nm Gate Lengths and 10-nm Fin Widths Applicable for the 45-nm CMOS Node”, IEEE Electron Device Letters, Vol 25, No 8, August 2004, p G. Knoblinger et.al., “Design and Evaluation of Basic Analog Circuit in an Emerging MuGFET Technology”, IEEE SOI Conference, Oct 4-6, C.Russ et al., “ ESD Evaluation of the Emerging MuGFET Technology,” EOS/ESD Symp., pp, , Sept., 2005